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Transcript of (AOPs): A Study in New Horizons Potable Groundwater ...nysawwa.org/docs/pdfs/Session 8.2...
New Horizons(AOPs): A Study in
Potable Groundwater
Application
Outline
Introduction
AOPs vs. Traditional VOC Treatment
AOP Chemistry Basics
1,4 Dioxane
Pilot Study and Results
Introduction
Presenter: Andrew Manfredi– B.S. in Chemical Engineering with minors in Environmental
Engineering, Chemistry, and Math from Manhattan College
– Four years of experience in water industry at H2M
Presenter: John Collins, P.E.– B.S. in Civil Engineering from Clemson University
– 14 years of experience in water industry at H2M
AOP vs. PTA
PTA moves contaminants to the air (liquid phase to gas phase)
AOP vs. GAC
GAC moves contaminants from the water to the media (liquid phase to solid phase)
AOP vs. PTA vs. GAC
AOPs destroys the contaminants within the process
AOP Chemistry Basics
‘Flow-through’ treatment similar to GAC
Unique: combines UV and chemical oxidant
Complicated chemical reactor
AOP Chemistry Basics
AOP in three steps:– Form oxidant
– Initial oxidation of VOC compound
– Subsequent oxidation of VOC
AOP goal = produce hydroxyl
radicals
Hydroxyl radicals (OH) are
strong oxidizers
Multiple ways to create:– Hydrogen peroxide + ozone
– UV + hydrogen peroxide (H2O2)
– UV + titanium dioxide (TiO2)
Oxidation
Species
Oxidation Power
[V]
Flourine 3.03
Hydroxyl Radical 2.80
Atomic Oxygen 2.42
Postively charged
hole on TiO2
2.35
Ozone 2.07
Hydrogen
Peroxide
1.77
Permanganate 1.67
Hypochlorous
Acid
1.49
Chlorine 1.36
Iodine 0.54
Hydroxyl Radical
UV light cleaves the O-O bond creating two hydroxyl
radicals:
VOC Breakdown
Really, really, really complex
Multiple pathways
Multiple intermediates
Very very fast
Determine rate limiting step
Organic
Molecule
Rate Constant
[mol/L-sec]
Chlorinated
alkenes
109 to 1011
Phenols 109 to 1010
N-containing
organics
108 to 1010
Aromatics 108 to 1010
Ketones 109 to 1010
Alcohols 108 to 109
Alkanes 106 to 109
VOC Breakdown
Still with me?
VOC Breakdown
1,4 Dioxane
WATER + CO2
AOP + GAC
1,4-Dioxane
That’s not regulated!!!
UCMR-3 Contaminant of Concern
So, it probably will be…
…and it’s a probable human carcinogen
HRL: 35ppb = additional 1:100,000 cancers
HRL: 0.35ppb = additional 1:1,000,000 cancers
Treat with AST? 10,000:1 A/W ratio
Treat with GAC? <30 day changeout for
80,000 pounds
1,4-Dioxane55 total entry points with
>0.35 ppb detection
13 water suppliers
Max: 33 ppb
79 total entry points with
>0.35 ppb detection
3 water suppliers
Max: 4.4 ppb
Pilot Study –
Bethpage Water District
Study: UV+H2O2
Goals:– Treatment Capacity
– Economics
– Regulatory Approval
– Operator Familiarity
Variables
Set-Up and Sampling
Flow Diagram
Results
Pilot Study - Variables
Flow vs. Residence Time vs. UV Fluence
Pilot Study - Variables
[H2O2] Dosage
PROPORTIONAL TREATMENT CAPACITY
Pilot Study – Set-Up
Incorporating Flow vs. [H2O2] Dosage
Flow
[gpm]
1.5 ppm 3 ppm 6 ppm 12 ppm
15
30
60Increase [H2O2]
better removal
of contaminantsDecrease flow
better removal
of contaminants
During each
event, take
influent/effluent
samples
Pilot Study – Sampling and
Run MatrixRun No. TCE Conc. Diox Conc. Flow [gpm] [H2O2] UV Power
1 1510 60 15 0 0
2 1510 60 15 0 100
3 1510 60 15 12 0
4 5000 60 15 0 0
5 5000 60 15 0 100
6 5000 60 15 12 0
7 1510 60 15 1.5 100
8 1510 60 15 3 100
9 1510 60 15 6 100
10 1510 60 15 12 100
11 1510 60 30 1.5 100
12 1510 60 30 3 100
13 1510 60 30 6 100
14 1510 60 30 12 100
15 1510 60 60 1.5 100
16 1510 60 60 3 100
17 1510 60 60 6 100
18 1510 60 60 12 100
19 1510 60 60 1.5 60
20 1510 60 60 3 60
21 1510 60 60 6 60
22 1510 60 60 12 60
23 5000 60 15 1.5 100
24 5000 60 15 3 100
25 5000 60 15 6 100
26 5000 60 15 12 100
27 5000 60 30 1.5 100
28 5000 60 30 3 100
29 5000 60 30 6 100
30 5000 60 30 12 100
31 5000 60 60 1.5 100
32 5000 60 60 3 100
33 5000 60 60 6 100
34 5000 60 60 12 100
34 Runs
Spiked with additional TCE and 1,4-
Dioxane
Vary flow at 15, 30 and 60 gpm
Vary H2O2 from 1.5 ppm to 12 ppm
Four runs at 60% UV power
Influent and effluent samples for
each run
Lots of data!
Flow Diagram
Influent
Effluent
Flow Diagram - RPZ
RPZ
Device
Influent
from Well
No. 6-2
Flow Diagram - Chemical
Chemical
metering
pumps
Static
mixer
Chemical
injection
ports
Flow Diagram – Flow Metering
Flow
meter
Flow Diagram – AOP Reactor
AOP
Reactor
Flow Diagram – GAC Vessels
GAC
Vessels
Flow Diagram – Sampling
Points
Influent
Sampling
Effluent
Sampling
Post
GAC
Sampling
Pilot Study – Mixing Test
Mixing Test– Determine steady state
– Measure influent and effluent [H2O2]
Time [min] Influent [H2O2] Effluent [H2O2]
1 5.8 0.02
2 6.6 3.0
3 6.0 5.0
4 7.0 5.8
5 5.9 6.15
6 6.4 5.7
7 6.8 6.7
8 6.3 6.2
10 6.3 6.4
12 6.4 6.4
15 6.3 6.1
18 6.3 6.2
Pilot Study – Mixing Test
0
1
2
3
4
5
6
7
8
0 2 4 6 8 10 12 14 16 18 20
[H2O
2]
TIME [MIN]
15 GPM MIXING TESTInf Eff
Reactor has
reached
steady state
Pilot Study – VOC Data Results
Results as expected
Took 86 VOC Samples
Took 68 1,4-Dioxane
Samples
Took 36 IOC Samples
Took influent/effluent/post
GAC H2O2 samples
Cherry picked certain runs to
show trends
65 68 68 70
9.4
1.2 0.082 00
10
20
30
40
50
60
70
80
0 2 4 6 8 10 12 14
1,4
-DIO
XA
NE
[P
PB
]
H202 [PPM]
1,4-DIOXANE REMOVAL - 60 GPMInfluent Effluent
Pilot Study - Results
85.5%
98.2% 99.8% 99.9%
Increasing
[H2O2]
Pilot Study - Results
6963 65
0 2.59.4
0
10
20
30
40
50
60
70
80
0 10 20 30 40 50 60 70
1,4
-DIO
XA
NE
[P
PB
]
FLOW [GPM]
1,4-DIOXANE REMOVAL – 1.5PPMInfluent Effluent
Increasing
UV Fluence
99.9% 96.0% 85.5%
Pilot Study - Results
1,7001,600
1,700 1,700
280.00
52.00 10.00 0.750
200
400
600
800
1,000
1,200
1,400
1,600
1,800
0 2 4 6 8 10 12 14
TC
E[P
PB
]
H2O2 [PPM]
TCE REMOVAL – 60 GPMInfluent Effluent
83.5% 96.7% 99.4% 99.9%
Increasing
[H2O2]
Pilot Study - Results
1,5001,6001,600
0.55 3.10 52.000
200
400
600
800
1,000
1,200
1,400
1,600
1,800
0 10 20 30 40 50 60 70
TC
E[P
PB
]
FLOW [GPM]
TCE REMOVAL – 3PPMInfluent Effluent
96.5%99.8%99.9%
Increasing
UV Fluence
Regulatory Issues
Suggest to utilize 70%, 80% and 90% UV ballast power
Hydroxyl radical scavenging demand
Impacts of increase CO2
GAC utilization to quench H2O2
Disinfection by-products
Reaction intermediates
Thank-Yous
Bethpage Water District– Board of Commissioners– Supt. Mike Boufis– Pete Schimmel
TrojanUV– Terry Keep– Alan Royce
Pace Analytical– Stu Murrell– Melissa Watson
GA Fleet– Jamie Saxe
Colleagues– Rich Humann, P.E.– James Neri, P.E.– John Collins, P.E.– Paul Ponturo, P.E.
Questions?
I never learn anything talking. I only learn things when I ask
questions.